Headwear, such as baseball-style caps, may include both fitted and adjustable variations. While fitted caps may be sized for a particular head dimension, adjustable caps provide at least some flexibility in sizing to fit differently-sized heads. An example adjustment mechanism for a cap includes a snapback mechanism which is often formed of a pair of plastic tabs that overlap and engage with one another when fastened. One of the tabs includes a plurality of protruding snaps while the other tab includes a plurality of holes for accepting the snaps. The snapback mechanism allows different head dimensions to be accommodated by engaging an outermost hole on one of the plastic tabs with different protruding snaps on the other of the plastic tabs.